Tandem-in-time mass

One of the prineiple uses of the ion trap is as a tandem-in-time mass speetrometer. Ions with a partieular m/z ratio fomied in the ion trap, or mjeeted into the trap from an external soiiree, ean be isolated by resonantly ejeeting all other... 

Appropriate use of RF and DC voltages means that some ions can be selectively retained and product ions generated. Some of these ions can then be selected and their product ions generated. In this manner, a fragmentation chain can be established. The ion trap is a typical tandem-in-time mass spectrometer, in which precursor and product ions are created and analysed in the same physical space ionisation and ion analysis, on the other hand, take place at different times ( MS/MS in time )- The operation can be repeated several times, making it possible to perform MS11. Ion trap mass spectrometry thus consists of ... 

Because of these powerful qualitative capabilities, FTICR mass spectrometry is especially useful for characterization of DCLs. Because the composition of the DCL cannot be statically defined, except when in equilibrium with the receptor, it is essential to be able to identify the components at this stage. Using FTICR MS, identification can be done by a combination of exact mass determination and tandem-in-time mass spectrometry to yield par-ent/daughter ion structural information. Although FTICR is an expensive option for combinatorial library characterization, it can provide the most direct information for ligand identification in libraries. 

Discuss the major differences between a tandem-in-spaco mass spectrometer and a tandem-in-time mass speciromolcr. Include the advantages and disadvantages of each l pe. 

Johnson, J.V. Yost, R.A. Kelley, P.E. Bradford, D.C. Tandem-in-space and tandem-in-time mass-spectrometry-tiiple quadrupoles and quadrupole ion traps. Anal. Chem. 1990, 62, 2162-2172. 

In tandem-in-time mass spectrometers all operations take place within a single-ion storage device, but at different times. The most common tandem-in-time instrument is the quadrupole ion trap (QIT). The ongoing development of a higher-sensitivity counterpart, the linear ion trap (LIT), will presumably lead to an eclipsing of the QIT. 

The quadrupole ion fiap (QIT) has developed into a highly successful MS/MS device [49]. It is a tandem-in-time mass spectrometer, meaning that all steps of MS/MS are performed in the same space but with a temporal sequence. A typical... 

Johnson, J. Yost, R. Kelley, P. Bradford, D. (1990). Tandem-In-Space and Tandem-In-Time Mass Spectrometry Triple Quadrupoles and Quadrupole Ion Traps. Amd. Chem. Vol.62, N°20, pp. 2162-2172, ISSN 0003-2700. 

Garrido Frenich, A., P. Plaza-Bolanos, and J. L. Martmez Vidal. 2008. Comparison of tandem-in-space and tandem-in-time mass spectrometry in gas chromatography determination of pesticides application to simple and complex food samples. J. Chromatogr. A 1203 229-238. 

---